title: Ten marker compounds-based comparative study of green tea and guava leaf by HPTLC densitometry methods: antioxidant activity profiling.
abstract: High-performance thin layer chromatography (HPTLC) method for the separation and quantitative determination of ten markers (catechins, flavonoids, and phenolics) in different extracts of green tea and guava leaf has been developed and the antioxidant activity profiles of the two plant extracts have been determined. Ten marker compounds have been resolved using silica gel 60 F(254) plates, toluene/acetone/formic acid (5:4:1  v/v/v) for markers 1-6, and toluene/ethyl acetate/formic acid/methanol (3:3:0.8:0.2  v/v/v/v) for markers 7-10 as the mobile phases. The high-performance thin layer chromatography densitometry was performed at wavelengths of 282 and 285  nm for the markers 1-6 and 7-10, respectively. Potent antioxidant activity and the presence of phenolics and flavan-3-ols has been observed for the guava leaf extracts suggestive of its use as an alternate economical source of antioxidants over green tea--the well-established food additive/nutraceutical agent.
authors.affiliation: Bioorganic Chemistry Division, Indian Institute of Integrative Medicine (CSIR), Jammu and Kashmir, India.
authors.forename: Imran
authors.initials: I
authors.lastname: Khan
authors.forename: Payare L
authors.initials: PL
authors.lastname: Sangwan
authors.forename: Sheikh Tasduq
authors.initials: ST
authors.lastname: Abdullah
authors.forename: Bhisan D
authors.initials: BD
authors.lastname: Gupta
authors.forename: Jagdish K
authors.initials: JK
authors.lastname: Dhar
authors.forename: Rajendran
authors.initials: R
authors.lastname: Manickavasagar
authors.forename: Surrinder
authors.initials: S
authors.lastname: Koul
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D028241:Camellia sinensis / Q000737:chemistry*; D002855:Chromatography, Thin Layer / Q000379:methods*; D003720:Densitometry / Q000379:methods*; D005419:Flavonoids / Q000032:analysis; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols; D031647:Psidium / Q000737:chemistry*; D013662:Tea / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D013662:Tea